(Contains Strong Language) Billie Joe Armstrong defended Green Day at the iHeart Radio Music Festival as he felt he and the band were disrespected. The band’s set was cut about 20 minutes so Usher could have more time on stage. Pissed and offended, Billie freaks out swearing followed by smashing his guitar. Billie Joe Armstrong has checked rehab just two days after throwing an anti-Justin Bieber tirade at at Las Vegas concert. The Green Day front man is “seeking treatment for substance abuse,” the band said in a statement released Sunday. iHeartRadio Festival Meltdown.Video Rating: 4 / 5